Scotchgard was invented in the 1950s when a researcher with the 3M Corporation, who was assigned to develop a lining for jet fuel tanks, accidentally spilled some test material on a co-worker’s shoe.

It’s basically sunscreen for outdoor fabrics. Patio furniture can get expensive. So can anything made with Sunbrella fabric. And that’s a big challenge where I live in Palm Springs—home to 120-degree ...